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TitleFood Mycology
TagsGene Expression Gene Fungus Wax Proteins
File Size40.7 MB
Total Pages427
Table of Contents
List of contributors
Chapter 1: Cross-talk between host and fungus in postharvest situations and its effect on symptom development
Chapter 2: Real time monitoring of ethylene during fungal-plant interaction by laser-based photoacoustic spectroscopy
Chapter 3: Spore formation in food-relevant fungi
Chapter 4: Dispersal of fungal spores through the air
Chapter 5: The germinating spore as a contaminating vehicle
Chapter 6: Heat-resistant ascospores
Chapter 7: Why do fungi produce mycotoxins?
Chapter 8: Mycotoxin producers
Chapter 9: Filamentous fungi as cell factories for metabolite production
Chapter 10: Hyperproduction of enzymes by fungi
Chapter 11: Association of moulds to foods
Chapter 12: Transport phenomena in fungal colonisation on a food matrix
Chapter 13: Molecular detection and monitoring
Chapter 14: Fungal volatiles: Biomarkers of good and bad food quality
Chapter 15: Wine and fungi – implications of vineyard infections
Chapter 16: Cheese and fermented sausages
Chapter 17: The colonizing fungus as a food provider
Chapter 18: Fungal protein for food
Chapter 19: Edible mushrooms: from industrial cultivation to collection from the wild
Document Text Contents
Page 2

Food Mycology
A Multifaceted Approach to Fungi and Food

Page 213

grape infection by fungi, which may be reflected on the level of a
mycotoxin in wine, namely ochratoxin A. This chapter deals with many
different aspects of fungal spoilage ranging from post-harvest problems to
mycotoxin detection, all related to the production chain from early grape
formation to the bottle of wine on your table. In Chapter 16 Stark covers
the fungi associated with cheese and sausages, which in a way display a
mixture of wanted and unwanted fungi.

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Chapter 11

Association of moulds to foods

Jens C. Frisvad1, Birgitte Andersen1 and Robert A. Samson2
1Center for Microbial Biotechnology, Biocentrum-DTU, Technical University of Denmark, DK-2800 Kgs.
Lyngby, Denmark; 2CBS Fungal Biodiversity Centre, Utrecht, The Netherlands.


The traditional division of filamentous fungi
has been between the food spoiling fungi,
which were considered opportunistic fungi
with no substrate preferences and animal or
plant pathogenic fungi with tight associations
to their hosts. Most food spoiling fungi have
been regarded as saprophytic organisms thriv-
ing on any substrate they could encounter and
they can indeed be isolated on many different
laboratory media. They can grow and differen-
tiate on minimal media containing only nitrate
and sucrose as nitrogen and carbon source, as
well as on complex media based on cereal,
vegetable, fruit and meat, such as peptones,
corn steep liquor, malt and yeast extract.
(Raper and Thom, 1949; Smith, 1960; Samson et
al., 2004c). However, as early as 1949 Wester-
dijk suggested that certain Penicillia were
associated to certain food substrates, such as P.
italicum and P. digitatum to citrus fruits and P.
expansum to pomaceous and stone fruits. These
associations were regarded as the exceptions
rather than the rule for filamentous fungi.
Several authorities (Thom, 1930; Raper and
Thom, 1949; Pitt, 1979; Ramírez, 1982) were of
the opinion that the many Penicillium species
they treated were saprophytic generalists
rather than species associated to specific natu-
ral habitats or processed foods and feedstuff.
Difficult taxonomy and lack of data may have
obscured the less obvious associations between
Penicillium species and habitats or food prod-
ucts (Frisvad, 1988; Frisvad and Filtenborg,
1988). Furthermore, using inadequate tech-
niques and methods would often make it im-
possible to distinguish between simple surface

contamination of a food product and true
infection resulting from the fungal-substrate
association. Fungi isolated from surface disin-
fected products are with some probability
thriving on the product and therefore associ-
ated with it, whereas fungi growing from non-
surface-disinfected products could be acciden-
tal contaminations from other materials, stor-
age facilities or the air (King et al., 1986; Fris-
vad and Samson, 1991; Samson et al., 1992;
Filtenborg et al., 1996; Hocking et al., 2006).
This applies not only to Penicillium, but also to
all other major food spoiling genera, such as
Aspergillus, Alternaria and Fusarium.
The associated mycobiota of a food product
can be defined as all the fungal species that are
able to infect and actively grow on the product
under harvest, storage or processing condi-
tions. In connection with food mycology and
safety, the fact that each fungal species found
in a food product produces a species specific
profile of extrolites is of particular importance.
An extrolite can be a volatile or non-volatile
secondary metabolite, an organic acid, an
extracellular enzyme or other outwards di-
rected biochemical compounds (Frisvad et al.,
1998, 2004; Frisvad and Samson, 2004; Larsen
et al., 2005). For example, only three of the
approximately 90 food spoiling Penicillium
species are able to produce penicillin (Samson
et al., 2004c). Among the extrolites, mycotoxins
and other bioactive compounds, such as ochra-
toxin or patulin, are of direct health concern.
The production of mycotoxins is highest and
most diverse under optimal conditions in a
laboratory and mycotoxins are only produced
in the food products during storage or process-
ing when conditions change to the advantage

Page 426

CHAPTER 19, Figure 1: A dense crop of mushrooms (top) is produced by the following scheme of cultivation of A. bisporus
according to the Dutch system (bottom).

Page 427

CHAPTER 19, Figure 2: Mushroom infected with Verticillium fungicola (dry bubble disease).

CHAPTER 19, Figure 3: Boletus edulis in a sixty-year old wooded bank of Quercus robur in The Netherlands.

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